He's a lover, not a fighter - smell, sex and civility

Efforts continue to dissect the neural basis of complex behaviors such as sex and aggression. A commonality in both these responses is the importance of olfaction. The opportunity presented by genetic ablation of a cation channel (TRP2), expressed selectively by the vomeronasal organ (principally involved in pheromone detection), has given rise to two independent Trp2(-/-) mouse strains. These knockout strains show a complete lack of male-male aggression and elevated sexual behavior that is directed at both males and females, an unpredicted and hitherto nonexistent behavioral phenotype in mice. Discerning a meaningful relationship between this phenotype and the neural basis of complex behaviors remains a challenge.